It is proposed to investigate which organ(s) or tissues are directly involved in the post-transfusion or irreversible hemorrhagic shock complication. Specifically, it is planned to study the water content and its changes in the muscle and adipose tissue and the surface pH in these tissues. At the same time, isoenzyme studies will be conducted to help direct the search for the tissue which releases adenylate kinase during the same phase. It is expected that these studies will narrow down the choice of possible organs directly related with the so-called irreversibility.